Replacing wheels and valve gear on HD 3 rail locos

[detheridge]

Hi folks,

perhaps Golden Fleece, Il Grifone, or anyone else can give further information.

I notice on the superb conversions and 'neverwazzas' in 3 rail locos you indicate that you swapped wheels and valve gear to produce various chassis.

How difficult is it, what tools do you need (particularly for quartering the new ones), and what do you have to watch out for?

Do you use extra tools such as the Hamblings wheel press to assist?

I'm posting from the viewpoint of someone who uses Romford wheels and axles only as a last resort :-)

 

Many thanks i advance

 

David.

[Il Grifone]

Hi David,

 

It's not too difficult to replace the wheels.

 

Unless you obtain new wheels (some are still available from Wrenn), a second hand set will already have cut splines in the wheels and quartering is automatic. They may need truing up however, if they were not removed with due care (lever off gently with a suitable tool - I misuse a screwdriver). 2 rail sets should be done from the non-insulated side. New wheels have to be quartered and require a substantial press or vice to force them on the axle. There is also a shortage of insulators for the crankpins. Obviously this does not matter for a 3 rail locomotive. I quarter by eye lining up the spokes and press the wheel on just enough to hold it. Then repeat for a second axle and then when these two run smoothly repeat for the third axle and so on. Once all the axles are running without tight spots they can be pressed home. Press rather than tap - finger pressure is usually sufficient. Sometimes the wheels are worn slack and a spot of Loctite or similar is needed to secure. Possibly it will  be found that one or more wheels do not run true. In this case rotate slowly to find the spot where the flange is closest the chassis block then lever gently at this point. Repeat until the wheel runs true. Dublo track is quite tolerant, so 100% truth is not essential.

 

The valve gear varies. Early examples were just press fitted but later ones were riveted over on the inside. This can be difficult to remove but pressing the crank pin hard home helps. Reassembly can be done by just pressing home the crank pin. Try to avoid early wheels as these have a small diameter stub which fits into the wheel and use thinner crankpins. The stubs are likely to be bent and are not compatible with later valvegear due to the different diameters. The return cranks just press home. On most locomotives they are inclined forward with the crank at bottom centre (Rebuilt Bulleid Pacifics are one exception). Lesser makes seem to be under the impression that they incline forward on one side and backward on the other. Dublo axles are conveniently 1/8" in diameter. Improving Tri-ang chassis* by fitting Dublo wheels requires 9/64" to 1/8" bushes (available from Romford/Markits**).

 

*  A long term project is fitting 4MT wheels to a Tri-ang 'Britannia' - everything runs nicely, but I have lost one of the pins that hold the return cranks....

** Usual disclaimer - other bushes are available.

 

I hope this is clear and helpful. It's one of those things that is easier to do than explain.

 

David

Edited May 22, 2016 by Il Grifone

[Golden Fleece 30]

Hi, I fully agree with David's comments although I do odd things slightly differently. Tapping off the wheels is easy but then as David says when Crankpins are riveted over on the back it is a pain in the rear. For these I use a little grinder in a Dremel to remove the riveted dome and then tap out the pin. Hopefully this is still usable but as David says a little loctite will help. Putting wheels on a Hamblings press is no good unless you modify it for the Dublo crankpin throws, which are not all the same. I line up by eye and then tap home with a pin hammer, but again as David says only so far to check for free running before tapping home fully. Be very carefull with the return cranks they can be easily bent or broken and again like David watch out for the different sized ones. At times I remove the nylon bushes and buy or make metal ones to de-insulate. The valve gear can be tricky to match up to other wheels. The old Duchess piston rod will pop out of the cylinder if used on a Castle chassis, I make small extentions to fit. A4 valve gear will foul both front and back if used on 2-6-4 wheels so the crosshead needs trimming. The major thing to watch out for though is when re-drilling any new axle holes make sure they are square to the chassis otherwise one set of wheels will be off the track.

 

I have just done another (better write up and photos later) but it needed a new axle hole about 1mm into an old one. I riveted a piece of 1/8" brass in situ before drilling it.

 

All this can be fun and a challange, BUT, it does not always go to plan and is very difficult to say if its hard or not depending on individuals capabilities.

 

If you try and get stuck don't hesitate to ask and I am sure David, myself or someone else can help.

 

Don't forget if new holes go wrong you can always put it back together as was.

 

Garry

[Golden Fleece 30]

I forgot to talk about the valve gear. If using the A4 type then you will most likely have to make a carrier to solder it to as it is only pinned to lugs on the chassis and not screwed as the others are. The others may also need their carriers cutting to clear wheels that are now in a new position. In a lot of cases you may be okay with the connecting rod etc lengths but at times these need shortening or new ones making.

 

If you are thinking of an A2 or A3 using Bachmann or Trix bodies (the Trix body is far better in my opinion than the old Tri-ang one) then you need to use a Wrenn A4 chassis. This is because the armature is behind the rear wheel which means a little easier to fit the pole pieces into the body. This still requires a lot of carefull grinding of the body and filing of the pole pieces. I will see what photos I have tomorrow when I am back at the PC.

 

Garry

Edited May 22, 2016 by Golden Fleece 30

[Golden Fleece 30]

Here are some modified chassis's.  Most still retain the standard axle spacing's, others have new axle holes drilled.

 

Garry

[Golden Fleece 30]

I thought the names of what parts the chassis's were would come up but as it has not here they are

1.Tri-ang 3MT, Dublo 0-6-2 with 2-6-4 valve gear.

2. Bachmann A1, Castle chassis, W/C valve gear, A4 pony truck and bogie.

3. Trix A3, Duchess chassis, A4 valve gear.

4. Tri-ang King Arthur, Castle chassis, City valve gear.

5. Late Margate Princess (full length), Duchess chassis, 2-6-4 valve gear.

6. Grinding of Princess cylinders to go around Dublo track.

7. Stanier 2-6-0 (Dublo 8F body untouched), R1 chassis, 2-6-4 valve gear.

8. 4F, R1 chassis new axle hole further forward.

9. B17, Castle chassis new rear axle further back.

10. 4F chassis.

11. Margate Schools, R1 chassis new rear axle hole.  Cylinders a little high probably should have been mounted from underneath

12. Schools chassis.

13. Bachmann V2, R1 chassis, A4 valve gear and pony truck.

14. 2 Trix A3's, one on the Duchess chassis and one on a Wrenn A4 chassis.

15. Wrenn Spam Can, A4 chassis, Barnstaple Boxpok wheels.  Valve gear to be replaced later with repro Wrenn style.

[Golden Fleece 30]

Here is a recent chassis modification.  Originally it was for the Bachmann J72 and was the 8F chassis with new holes front and rear using the distances from spare coupling rods from an A4 etc when its wheels were used on a different chassis.  The rear hole would run into the old one by 1mm so the hole was plugged with brass rod and riveted over before the new hole was drilled.  As it worked out the motor was still too high for the small body so I had to think what it could now be used for.  It turned out that the Bachmann 43xx was a very good close fit to the axle spacing if I used spare R1 wheels.  The angle of the camera shows it not aligning with the splasher but straight on it is close.  I will sort out some slide bars etc, hopefully the Castle ones and a new body in full BR lined green will be fitted.

 

Garry

[Glasairman]

I have started to overhaul my childhood HD/EDL collection and want to strip down the chassis for a complete baremetal repaint. I stopped however as I could not find a source online for the rivets. As the imperial versions are probably now very hard to get, I am not so purist as not be prepared to bore out and use metric, which are probably easier to get here in Germany

[Il Grifone]

Hi David,

 

Wrenngalore still have crank pins on eBay. They seem to be aluminium however.

https://www.ebay.co.uk/itm/WRENN-model-railway-TWENTY-FOUR-Con-Rod-Pins/400055875553?hash=item5d253037e1:g:jzAAAOxybqpRh7kp

 

(To be pedantic, they are coupling rod pins! - I have used these and they do fit Dublo wheels (mine anyway). Dublo connecting rods are either held on by the return crank of the Walschaerts gear or a large headed pin on the Castles.)

 

It is possible to reuse the originals. The early type just pull out, but the later ones have been rivetted over on the inside. Either leave well alone or, with great care to not damaged the wheel, the pin can be driven in tight and the rivetting filed off. The crank pin can then be pulled out.

For a repaint I would just paint over the original paint on the wheels.

However it is really best to interfere with Meccano's work as little as possible. They had all the jigs and presses to ensure a perfect result every time.

 

Only touch the valve gear rivets if a repair is necessary.

[Wolseley]

On the subject of removing and replacing wheels on Dublo 3 rail locos, I have just removed the wheels and axles from a scrap 0-6-2T chassis, with the intention of using them on the construction of a chassis for a DJH kit.  I am at the moment undecided as to whether to start with a Caledonian 34 class 2-6-0 or a Highland Jones Goods but, regardless of which one I end up doing first, I have one stumbling block to overcome.

 

When I match up the wheels and crankpins (or coupling rod pins if you prefer) the Dublo crankpin won't fit through the hole in the DJH rod.  There is also not enough metal around the holes to enable me to safely turn them into something that will accept the Dublo pins.  I cannot use the original Dublo coupling rods, as the wheel spacing is quite different and I don't really want to make new ones if it can be avoided so, would the best solution be to cut off the bits with the holes on the Dublo rods so that I have, in effect, six small washers with Dublo rivet sized holes in them, solder them over the holes in the DJH rods, and then open up the hole in the DJH rod until it is Dublo sized?

 

Or is there some sort of crankpin out there that will fit into the Dublo wheels but presents a shaft (if that be the right word) for attachment to the coupling rods that is almost half the width of the Dublo rivets?

[Il Grifone]

I have a feeling that Romford crankpins can be persuaded to fit Dublo wheels* or a short piece of suitable tubing could be used to make a bush. In some of my early 2 rail conversions I used wire insulation as an insulating bush.

 

* They are threaded 10 BA and will fit Tri-ang wheels, but I'd have to check the fit on Dublo wheels. They might require a bit of bodging skilled micro-engineering.

Edited July 31, 2019 by Il Grifone

[sagaguy]

Before i had a lathe,i used 1/16th" steel snaphead rivets now available at eileens emporium or ebay under model engineering.

 

                 Ray.

Edited July 31, 2019 by sagaguy

[Wolseley]

On 01/08/2019 at 05:12, Il Grifone said:

I have a feeling that Romford crankpins can be persuaded to fit Dublo wheels* or a short piece of suitable tubing could be used to make a bush. In some of my early 2 rail conversions I used wire insulation as an insulating bush.

 

* They are threaded 10 BA and will fit Tri-ang wheels, but I'd have to check the fit on Dublo wheels. They might require a bit of bodging skilled micro-engineering.

 

Thanks for that.  I don't have any Romford crankpins to hand, but I think I know where I can get my hands on some.  Sounds like it's worth a try.

[Wolseley]

On 01/08/2019 at 05:12, Il Grifone said:

I have a feeling that Romford crankpins can be persuaded to fit Dublo wheels* or a short piece of suitable tubing could be used to make a bush. In some of my early 2 rail conversions I used wire insulation as an insulating bush.

 

* They are threaded 10 BA and will fit Tri-ang wheels, but I'd have to check the fit on Dublo wheels. They might require a bit of bodging skilled micro-engineering.

 

Thanks for that.  I don't have any Romford crankpins to hand, but I think I know where I can get my hands on some.  Sounds like it's worth a try.

 

I screwed in a Romford crankpin into a Dublo wheel and found that it not only went in, but it seems to have cut its own thread in the wheel and stayed put after it was screwed fully home.  And the connecting rods from the kit I am assembling (unsurprisingly) fitted the crankpins perfectly.  As you suggested, all it needed was a bit of bodging skilled micro-engineering.

[hayfield]

If the hole is a bit tight it might be worth buying a 10ba tap (plus holder) and the appropriate drill, I did this as I have a few older Romford wheels that need drilling and taping, its quite easy to do, I also bought an 8ba tap which also has come in very handy in both building and converting chassis

[Il Grifone]

I bought my taps from Proops on eBay (usual disclaimer).